The guy has certainly stuck with it. I just don't see it. Look at
the nightmare problems of the Osprey and the Harrier. The VTOL is the
problem with the thing. Plus having no wings to speak of, it would
seem to take quite a bit of energy just to keep the thing in the air.
I also see it as a gas guzzler. He has never more than hovered just
off the ground, using ground effect primarily, I would imagine.

Cars are pretty efficient. A human can push one down a level road.
Picking one up off the ground is quite another matter.

Same with airplanes. A guy once pedeled an airplane across the
English channel (over 20 miles..... I like to think Wilbur and Orville
would have said "Holy ****!!!"). Try and imagine a pedal powered one
of these things. I can't.

Bill Guess Happy Kitty Hawk Day. I like Google's Home page
tribute to the Wrights